Interview: "CAE services from a single source"

In addition to systems simulation, TECOSIM has also offered multi-body system simulation (MBS) in its portfolio for a number of years now. It aims to supply customers with "everything from a single source" as a full CAE service provider. We spoke to the new TECOSIM Managing Director Martin Westerwald about this sub-discipline in computer-aided engineering.

Mr Westerwald, when exactly is multi-body system simulation (MBS) the best choice?

For numerical calculations wherever complex mechanical systems are used in which several components are in motion. The aim is to ensure that individual components interact with one another to an optimum extent right from the development stage.

In which specific areas does TECOSIM use MBS?

We use multi-body simulation for individual client orders, such as complete vehicle projects. We also produce MBS models of vehicles within our virtual benchmarking solution TEC|BENCH. With TEC|BENCH, we provide our clients with detailed finite element models (FE) of series vehicles for comparison with competitors regarding aspects such as driving dynamics, NVH studies and crash simulations.

What advantages does MBS offer clients?

They can use the models for all types of driving dynamic simulations, for example, or calculate section loads to establish service life. In TEC|BENCH calculations, we achieve the high pattern quality required for MBS from the precise data which the virtual benchmark process provides on elements such as kinematic points or mass properties of the relevant components. We also measure the quasi-static, dynamic characteristics of the rubber joints, springs and hydraulic vibration absorbers mounted in the chassis. These are also incorporated into the model.

What exactly does the client do with MBS models?

A manufacturer can carry out extensive driving simulations with a virtual vehicle developed in this way, for instance. Typical examples are steady-state skidpad testing, lane change and braking on bends. If a test track is available in digitised format, the development engineer can also drive along the whole track in the virtual vehicle. Unlike real chassis adaptation, a large number of setting options and their interaction can be tested, thus achieving the optimum result.

MBS model for a complete vehicle

Not all variants are tested on the computer either. What approach do engineers take here?

We make use of statistical test planning or DOE – design of experiments. This method allows us to identify key variables using the lowest possible number of calculations. A functional correlation between a parameter and a command variable is also established. This provides the opportunity to achieve an optimum setting.

As you would expect, this process does not replace real vehicle adjustment. The idea is to give test engineers a practical starting point for their work and identify the most influential correcting variables.

What objectives is TECOSIM pursuing in the field of MBS?

We expanded our portfolio with the MBS and systems simulation sub-disciplines a few years ago to strengthen our position as a CAE market leader and establish ourselves as a full CAE service provider. We offer our clients all CAE services from a single source through our expert team. As a result, our clients do not need to work with several development partners. Another advantage that we offer is extensive expertise in the international automotive industry. We are familiar with many vehicle variants from our TEC|BENCH projects and know where and how MBS is used in the industry.

MBS model for a rear axle

What industries do you use MBS in?

Basically, we do not restrict its use to any particular sector. Using MBS is feasible in any industry. However, the focus is clearly on the automotive industry, agricultural and construction machinery and the aerospace industry.

TECOSIM now offers an interactive online demonstrator for systems simulation. Does interlinking multi-body simulation with systems simulation actually make sense?

Yes, because it is increasingly less important to examine systems separately; it's more relevant to study how they interact. Interlinking the two is also useful if we need to model items such as actively controlled components in a vehicle. Examples include active steering of front and rear axles, ABS/ESP, adjustable dampers or active roll stabilisers. Co-simulation of MBS and systems simulation software can help to provide realistic rendering of vehicle hydraulics.